Refrigerating apparatus



Aug. 12, 1930. c. BIRDSEYE REFRIGERATING APPARATUS Original Filed June18, 1927 as s N a m a a a o A u: N I N a 6 h a Q m Q N 4 Sheets-Sheet lATTORNEY g- 1930. vc. BIRDSEYE 1,773,081

REFRIGERATING APPARATUS Original Filed June 18, 1927 4 Sheets-Sheet 2NMJMVW, am 3 6m x W Wm .wN Q WW 1 Y NNAW 551::255?:if B i A TTORNE YAug. 12, 1930. c. BIRDSEYE REFRIGERATING ARPARATUS Original Filed June18, 1927 4 Sheets-Sheet 3 M8 M7.- INVENT OR A TTORNE Y g- 12,1930- c.BIRDSEYE 1,773,081

REFRIGERATING APPARATUS Original Filed June 18, 192.7 4 Sheets-Sheet 4Ma. 8% INVENTOR ATTORNEY Patented Aug. 12, 1930 UNITED STATES PATENTOFFICE CLARENCE BIBDSEYE, OF GLOUCESTER, MASSACHUSETTS, ASSIGNOR, BYKESNE A8- SIGNMEN TS, TO FROSTED FOODS COMPANY, INC., 01 DOVER,DELAWLRE, CORPORA- TION OF DELAWARE Original application iiled June 18,1927, Serial No.

BEFRIGERATING APPARATUS 199,898. Divided and this application filed July7,

1928. Serial No. 290,976.

chine or apparatus is useful wherever. it is desired to quickly chill orfreeze an article, I 5 shall in this specification illustrate itsoperation as applied to .the preserving of food products byrefrigerating the same, preferably by .quick freezing such a productinto a frozen block in which the pristine qualities and flavors of theproduct are retained for a substantial period after the product has beenthawed.

In my coendingapplication Serial No. 199,693, filed June 18, 1927 (ofwhich the present applicationis a division), I have disclosed a novelmethod ofcooling or freezing food products or comestibles, such as fishand meat, which results in preserving the natural qualities and flavorsof the comestible substantially unimpaired for a substantial period oftimeeven after the product has been thawed. By my new method andapparatus I am able, by means which are economical andcommerclallypractical, not only to eflect any desired degree ofrefrigeration but also to quick freeze a comestible into a compactfrozen block, the comestible, if desired, being fro'zen'in the packageorcontainer in which it is to be marketed. v

For example, an important field of utility :for this machine orapparatus resides in the preparation of dressed fish for the market. vAccordin to the method which I will illushate, I rst form the fish intoa compact mass from air so far as possible. By reducing the volume ofairand the voids in the package, the block may be frozen more rapidlyand efiiciently and the opportunity for Preferably the blockforslab isencased infthe wra PQI'QI carton in which it is later tobe mar eted,andit .is advantageous tomake' i this block comparativelythin so that'itwill be more quickly frozen throughout its mass. The block orslab offish so prepared is next frozen so rapidl and at such a lowtemperaturethat the cell ities and flavors of the fish are retained and block orslab, consolidating it. and freeing the.

s of the fish tissue are substantially unbroken. Thustheoriginal qualtheproduct returns substantially to itsoriginal condition upon thawing.

The present invention rovides a machine with which articles, inc udingcomestibles such as that described, or of any other suitable character,can be frozen very quickly or rapidly chilled to any desired degree andat an entirely reasonab e expense. For example, the invention makes itpossible for the first time, so far as I am aware, to produce in apractical and commercial way a compacted quick frozen block of fo'odproductsor comestibles, preferably frozen in the package in which it isto be marketed. Such a block can be stored for a lon period of time,transported and marketed at a distance, and then after being thawed willbe found in substantiallythe same condition as before freezing. Y

I will now describe a preferred embodiinent of my invention by referringto the accompanying drawings in which like reference numerals indicatesimilar parts through out the several views.

'ratus constructed in accordance with my invention, looking at the frontor feed and thereof (in thisviewthe cover isremoved from the freezingchamberof the nearer machine and the spray pipes for the upper conveyorare not shown) v Figure 2 is. a side elevation partly in longitudinalsection of the front end and central portions of said apparatus;

Figure 1 is a perspective view of an appa- Fi ure 3 is a side elevationin continuation the apparatus; n

2 .Figure 4 is ,packa :"fend o the apparatus. I

the multiplication of bacteria is reduced; Figure 5, is across-sectionalyiew, artly in end' elevation, as upon line 5 f5 0 Fig,"ur

Figure 7 is aperspective view of a coin-- 1 my invention; and

F gure 8 1s a View of the cover.

horizontal cross-sectional 'of Figure 2, showing the discharge end of Ia perspective view of thereceiving trough at the discharge Figure 6is across-sectional isometric view at the discharge end of the freezingchamber;

said package immediately beneath v leg.

,pleted package prepared in accordanoe with specific embodiment of the aparatusillustrated in said drawings, the re erence numerdl 1 indicates alower belt conveyor, substantially parallel to which and above which isan upper beltoonveyor 2. The article to be refri eratedQshown in thedrawin as} ro uct acked in cartons3, pre gig of an tantia uniformheight, is carfrom one end the machine to the other between the up rreach of the lower conveyor 1 and the ower reach of the upper conveyor2. It is to be understood that said con veyors each pass aroundappropriate drums or 4, so as to provide for continuous.

operation in one direction, and also that the lower reach of the upperconveyor and the upsch of the lower conveyor are both movmg atsubstantially the same speed in the same direction. As the apparatus ispreferably constructed, the upper conveyor is shorter than the lowerconveyor, thus afiordinrg accommodation at the end at which the a icleis introduced, to deliver said article to the lower conveyor'withoutinterference by the a per conveyor. After said article has been eliveredto the lower conveyor, it then passes beneath the upper conveyor and incontact with both conveyors. The particular apparatus shown in thedrawings, and more y in Fig. 1, is a double machine, that Y is, onein'which there are two pairs of con= "pm, but this may be altered toemploy only oneor as many-as found necessary or desirable. The two, airsof conveyors are and from t is point on I will refer to and describe themachine as if consisting of, one pair.

The apparatus furthermore includes a suitable framework 5 and adjustablebearings 6 at feed end of the \machine for the axle 5g wheel 48%;eichl-lconveyor, with y temig means w ic proper tension may'beapphed tothe conveyors. The conveyors are preferably actuated simultaneousltfi'oma source of power, such as a motor 9 see Fig. 3) throughappropriate drive shown, said motor actuates a worm I0 hereinillustrated as upon the motor shaft. Said worm is in mesh with a worm I!at the upper end of a vertical drive On an vertical drive shaft areworms 18 and 14 for the upper and logpr conveyors respective y, per worm13 in in meshwith a worm'yieel 15 onthe axle 16 for the driving wheel'or drum of the upper conflict, and the lowerworm 14 is in mesh with asimilar worm wheel 17 on the axle 18 for the driving drum of the lowerconveyor. Both etirveyors will therefore be actuated at the speed byutilizin worms and worm wheels of the same an character.

conveyor is preferabl arranged to have a vertical adjustment, t isad'ustment substantially the same at oth ended! the machine as shown.The framedrum. At the drive'end of the machine each housing 20 includesa gear case 21 for the upper worm 13 and its worm wheel 15. The driveshaft 12 and worm 13 have a sliding slot and key engagement 22 of ausual kind, so that as the housing 20 is moved up and down there will beno interference with the o ration of said worm and its worm wheel.ertical adjustment of each housing as a whole is obtained by means ofvertical screws 23 at each side of the said housing and operated throughbevel gears 24 (Figs. 1 and 5) on the upper end thereof in mesh withcooperating bevel gears 25 on a horizontal cross shaft 26, which in turnhas an appropriate operating arm 27 on the outer end thereof. Thestructure and support for the upper adjustable conveyor and the drivemeans for both conveyors is such as to afford ready adjustment and aconstant driving of the two conveyors in perfect synchronism.

The lower reach of the upper conveyor and the upper reach of the lowerconveyor pass longitudinally through a suitable chamber 28, the walls ofwhich are of heat insulating construction so as to conserve the coolinmedium as much as possible and also to aid in the rapidity with whichsaid medium may effect its purpose. Said chamber 28 has an appro )riateremovable, top cover 28. Runnmg t rough said chamber 28 are longitudinaltracks or supports located beneath the edges of the conveyors, thesupports for the upper conveyor being more fully described below and tosupports for the lower conve or being designated by numerals'29, 29

5 and 6). These supports 29, 29 extend longitudinally under the upperreach of the lower conveyor in a horizontal plane and close enough toether to permit a considerable pressure to be applied to the conveyor orbelt without bending or flexing the same.

Support for the lower reach of the upper belt is herein shown ascomprising a pair of channel irons 30, 30 which run parallel to eachother, and substantially under the longitudinal edges of said belt asshown in Fig. 6. Along the longitudinal upper margin of the side wallofeach of said channel irons, I adjustably secure an angle iron support31, with its de ending flange frictionally held to the channe iron 30 atintervals by clips 32, thus enabling the upper flange of support 31 tobe adjusted quite accurately in a longitudinally horizontal position,even though channel irons 30, may sag or otherwise be out of truehorizontal alinernent. The said upper flange of support 31 projectsinwardly ever the top of said channel iron support 30. Preferably thejuncture between the vertical and horizontalflanges of said angle iron31 is rounded or curved rather than angular, and on this curved edge andprojecting inwardly over the angle iron is secured a resilient or springmetal strip 33, here shown as faced with a strip of fabric 34. The partsare so positioned and related that the margin of the lower reach of theupper belt will rest upon the upper margin of the facing strip 34 and,by its own weight or the application of additional weight, be made todepress the facing strip and spring strip, thus securing constantcontactirrespective of irregularities 1n the belt or support therefor.

The supports are so arranged that liquid on the upper conveyor inflowing offthe side edges thereof will be carried also over the outsideof said facing strip 34 and on the outside of support 30 and thence dropdown: wardly past said support 30, which extends below the planeof thelower conveyor, thereby preventing said liquid from entering betweensaid conveyors. The close engagement of theunderside of the belt withthe fabric strip 34 will prevent the freezing liquid from creeping alongthe under side of the upper belt and thus gaining access tothe spacebetween the belts. As an added precaution, I have shown an apron 35securedon the inside of the channel support 30 and depending therefromsubstantially to the bottom of the chamber. 28 to prevent vapor orsplash from the upper beltin any way gaining access to the space betweenthe belts.

The weight of the lower belt, to which isadded the weight of thearticles being frozen,

and the .p ressure of the upper. belt, makes a liquid tight contactbetween 'thelower belt and its supporting members 29, which prevents thefreezing liquid passing beyond these edge supports and therebygettinginto the space between the belts. I may also secure an apron 35'to the outside edges ofthe outside supports 29 anddepending therefromapproximately to the bottom of chamber 28 to further prevent liquid,vapor or splash from the lower belt in any way gaining access to thespace between the belts. If desired, the aprons 35 and 35 may extend toand make a seal with the bottom of chamber 28 to further avoid anyvapor-of the freezing liquid gain ing access to the space between thebelts.

By the means just described, I am enabled to use a cooling solutionwhich would ad'- versely affect the product to be refrigerated if itshould come in contact therewith.

The conveyors which I use are preferably imperforate metal belts whichshield the ar- "ticle being frozenfrom any freezing fluid which is beingused, and yet the arrangement is such as to enable the conveyors to bein direct contact with the article so as to obtain rapid cooling thereofby conductivity. It

may be here noted that the prevention of contact between the freezingliquid and the article being frozen is further aided by employing anupper conveyor of greater width than the lower conveyor.

. In the preferred construction of apparatus, the channel supports 30are carried by hangers from riders on housings 20 so as to be moved upand down with said housings when an adjustment for a different sizedarticle is desired. In carrying out this feature of the invention, thesupporting channels 30 are shown as projecting from the end of therefrigerating chamber to a position between the several vertical guiderods at both ends of the machine. Since support for each end of eachchannel iron 30 is by similar means, only 'one such support will bedescribed. On the outside of the channel 30, substantially paral: lelthereto, is a lower bar 36 forming part of said hanger. This bar 36 isshown attached at a central point by a-bolt 37 and bracket 38 to saidchannel support, and at each end of said bar is secured a strap 39'whiclrdepends thereto from the previously described housing or rider20, this support being effected through the agency of a cross rod 40(Fig. 5) extending across from one side of said rider to the other. Eachend of each cross rod 40 is adjustablymounted on the rider by beingsecured'to a cleat 41 having elevating set screws 42 at its cornerswhich-rest upon the top of the rider for raising said cleat to anydesired position. Lateral movement of said cleat is prevented by centralVertical studs 43 which are slidable through the cleat and whichprojectupwardly from a fixed position in the rider. By this means, thechannel supports 30may be independently adjusted with respect to theupper belt wheels.

Suitable spray pipes 44 are arranged above the lower reach of the upperconveyor and below the upper reach of the lower conveyor within thechamber 28. In the present showing, these spray pipes are shown in lonitudinal sections, with a feed pipe 45 lea ing to each section, was tosecure an adequate spray under proper pressure of the cooling fluid ormedium. Where the fluid is li uid, it is desirableto' drain the same offan re-use it, so

be made. If the aprons 35 and 35' make a seal with the floor of chamber28, additional drain pipes should be used.

It is desirable to prevent the cooling fluid from passing out of thecooling chamber along the upper surface ofthe lower reach of the topbelt, and to prevent this from occurring,the top pulleys are preferablyadjusted with relation to the bottom pulleys so that the distancebetween the pulleys is greater than the thickness of the product whichgives 'a. slight slope to the lower reach of the top belt is preferablifront or f ed thermostat & the present Show tothe eudofthetankby has lo'tlldin at both ends. This slope is shown at the feed and Lin Fi 2. Thisslope tends to cause an fluid on-t belt at that 'tion to flow bac towardsaid chamber. ore 'tive means may also be provided for he ding the fluidback, such as a transverse wiper 47. This should be of a constructionnot affected bythe severe .coldto which it is sub] ected so as tohecomestiff and useless. As one ractical form of. wiper, Ilhavo shown in ig. 6an in ite box filled with cotton waste or other soft material 48, withthe lower side closed by}: flexible material 49,.such as canvas, whichbenrson the entire width of the belt. The wipe; box; is confined betweenpieces bolted v 7 bolts and pressed toward the belt by a sprf 51. Such awiper used at the entrance and enttothe amber 28 for each belt, the onefor the upper belt actin of lower reach, and at for the lower beltacting upon the under side of the upper reach.

q the front or feed end of themachine, it is preferable to extend thelower conveyor asitbpaceive thearticle thereon before introducingit'between said conveyors. At this M m tutti1 of ti}; logverflc onveyaor Irovie es 2 i.1 or Eu ati tlg centergd g the articl These g3: eaarepreferably arranged one at each 8 wardeach other in the direction ofmovement ofconveyor. Where the product is of regular shape, aawithcartons ,3, the guides may be so positioned that he cartons will bepushed together transversely of thebelt beforeentry underthe upper elt.

Fox-reasons e meansherein for desired pressure on the upper ohm 1 antherefore upon the article pass.

. convey rs. Whil the weight b i thdupperconveyor belt itself mays'uffioe'in'apme instancemf prefer to supplement ing by" of apluralityof s aced rollers 53 u nand supported the upper ofr; lowerreach of theupper-belt transversely thereof. Each of said rollers y projectingcentral pintles fi'iflmd'i 5) which enter appropriate holes in ijfdownwardl entmding-flange of an angle iponpfi, sai iron bein'g dividedinto sections which permit corresponding series ofrollera to independmtladyust themselves to of VI. Each section of angle iron 5 is looselyhinged to adjaeent sections, andthe'sections are also anchored at thefeed end fas by straps 56, ex-

tending m 8.58mi portion of the frame worklto anchor the rollers frommoving longitiiiiinllly with the belt (see Fig. 2).

This construction makes .a floating pressure with} ininimumoffriction.The rollers are upon the upper sideforwardly infrontof the upperconveyor so Y of theconveyor, sloping inwardly to does not disintepreferably positioned quite close together, and the first one 57 in theseries, is also preferably heavier than the rest to secure initialpositive action thereof on the article to be refrigerated. Whereoccasion requires, additional weights 58 (Fig. 5) may be added byresting the same on the horizontal flanges of the angle irons 55.

At the discharge end of the apparatus I provide, in the present showing,a short chute 59 to a trough 60, arranged herein in alinement with thedirection of movement of the article from the conveyors. In said troughI preferably provide a smooth sheet of ice 61, upon which the productwill slide with a minimum of friction on leaving the conveyors and chute59. This acts as a convenient form of reservoir for reception of thearticles from the conveyors, and will' also serve to clean the bottom ofthe article from any foreign matter.

Asum example of a usefulapplication of my invention, I will describe itsa plication to the freezing of a packaged food product, such as dressedfresh fish or meat, whereby said food product is quick frozen in thepackage or container in which 'it is to be marketed. The packagepreferably comprises a suitable container, such as the cardboard carton3', which may be and is preferably waxed or otherwise rendered resistiveto the passage or absorption of moisture. For further protection, thesaid container should preferably be lined with, or the contents wrappedin an appropriate waxed aper or other moisture proof material 62. haveattainedsatisfactory results by the use of a r r P a I whichI willpresently explain, '1 alhmp'referablypro ed vegetable parchment paper,which to with exposure to moisture. The para coating resists the passaof moisture and keeps the pa er from stic ing to the contents. As I preer to carry out the invention, the container 3' is preferably positionedwith the cover open and the protective material 62 placed therein priorto the introduction of the food contents. With the container thusstandin open, a layer of the food product is laced m the bottom thereof.If the food pro act, for instance, is fish fillets, as indicated in Fig.8 the fish, either as a single fillet, if of suitable size, oraplurality of fillets if required, is laid into said container. Thefillets are. of the usual irregular shapes when inserted in thecontainer, and the parts which are too wide to go into the containerflat may be crumpled, folded or squeezed to get them in, endeavoring sofar as practicable to press the extra width of the fish toward the partof the container where the fishis not so wide. After the several layersand separators are inserted, the moisture roof lining or rotectivematerial 62 is lai over the top and the cover closed. By filling thecarton as completely as possible with the food product or overfillingit, I insure intimacy of contact between the various layers or parts ofthe food, and between the space between the conveyor belts. The filledpackages may be loaded into an open ended tray of suitable size. asshown at 67, Fig. 1', from which they can be readily-delivered onto theupper reach of the lower conveyor belt and advanced into the spacebetween the two belts, arranged closely side by side and end to end, andthence carried into the freezing chamber. The speed of the conveyorsmaybe adjusted to move the article through the freezing chamber in thelength oftime neces-:

sary for freezing, or the article may-be advanced into the chamber bythe belts, the belts stopped and the article retained in the chamber thedesired length of time, when the'belts can be again put in motion todeliver the article from the machine. The vertical position of the upperbelthaving been adjusted in accordance with the thickness of the packageto be treated, the packages as they are carried forward by the lowerbelt will-be en-- gaged by the lower reach of the'upper belt. The lowerbelt offers a substantially unyielding support to the package, and the uper belt is pressed downwardly on the pac age by its own weight and bythe pressure rollers. whenthey are used. The result is that with aproduce that is comparatively yielding, the massis compacted, theproduct will tend to fill any voids in the carton, and any unevennessesare flattened out sothat the roduct presents substantially even flat,sur aces ofsubstantial area, immediately juxtaposed against the sides ofthe carton, withwhich the belts are in contact. This insures "a, min=imum of insulating air layers or spaces, and a heat conductive contactover a substantial portion of the surface area of the block of foodproduct, which results in effective heat transference throughout themass. of the product, and uniform and complete freezing in the minimumlength of time. The character of the package as above described retardsany evaporation of the natural moisture of the food product, and anytendency to a loss of moisture from the package is further retarded bythe intimate contact of the belts through which moisture cannot pass.

Also, in the course of freezing, the food product will expand, and it isdesirable that this natural expansion should, so far as possible,-becaused totake' place in such manner as to fill out the container and yetnot bulge or distort it, in order to increase the intimacy of contactbetween the various portions of the contents and between the contentsand the container,w"with' resulting uniformity and rapidity of freezing,and to insure that the completely frozen ackage shall not be bulged ordistorted, ut shall be sightly and regular in shape. .4 This desirable.result is insured by my apparatus by the holding of the package duringthe freezingperiod between the metal belts, which press on the packageat top and bottom.

I have referred in this specification to quick freezing. While I amunable to define quick freezing in terms of exact temperatures orperiodsof time, the phrase will be readily understood by. anyonefamiliar with the freezing of comestibles. Freezing may take.

place practically,instantaneously, as by liquid air, or it may re uiredays, as in the usual refrigeration in refrigeratin rooms. In the caseof such comestibles as sh or meat, for instance, if thefreezing'consumesany substantial period of time, theflesh is injuriously affected and itloses its natural flavor and qualities. By quick freezing I meanfreezing in a su ciently short spaceof time so that the cells of thefood product are not disrupted or'broken and whereby the frozen block,throughout its mass, retains itsnatural qualities,-substantiallyunimpaired. I

:As an example of a satisfacto application of my machine to thequickzeezin of comestibles, I would state that Iattain highlysatisfactoryresults in freezing cartons, two inches thick, packed asabove described with fresh meat or fish, b passing such packages throughthe belts o my machine, and permitting-each carton or package to remainunder pressure in the freezing chamber, which is 37 feet long, about onehour and a quarter, while the belts are being sprayed with cal-' ciumchloride of about 33 'Baum, maintained at :an average temperature of 45below 0 F., the freezing fluid being supplied to the belts at'the rateofabout 200 gallons per minute. Of cours'e,...these figures can be variedwidely according to circumstances and other freezing mediums, can beused.

It is well understood that, food products consist ofa diversity ofelements with varying freezing points, and that the freezing points ofsome of these elements are so low that incommon commercial practice mostfood products are never-completely frozen. I therefore mean byfreezing'the congealing of some or most of the constituent elements ofthe food. a

While I have illustrated and described in detail an embodiment of myapparatus which I have found useful, I do not desire to be limited. tothe specific details thus illustrated and described; but intendto coverall appa- 00 chm aim ia':-

l Hplates supported, at Wei relation and, adiudnbla an their to a;compress betwetirthem food In scurryin thick- :amnta' and plates attoeii ween, whereby said food is finial througgttlwaucyiuf plates. 1; img gods comendlau: metai'belts ems metal film support for autism an em erse rate an w W 1H g g mi plate-the um surface of I v a plate with my mlmeans to Ma se s home said plates an "automatically to dem 9 r v asecond im fooenplate with any defprmra a food product onsaid" aMlgaaidfintplatnwherebysaid prod- ,v" to I agency of act will becompressed between said plates, and means to freeze said product whilecom-v thueducrdbedm invention, what pressed between said plates.

8. An apparatus for freezing foods comprising two endless imperforatemetal belts arranged in parallel relation and adapted to engage betweentheir adjacent reaches a food product, means to move said belts insynchrouim and-meansto freeze a food product while engaged between saidbelts.

9. An apparatus for freezing foods comn'sing a metal plate adapted toengage a ood product, a second plate supported in spaced relation tosaid first plate, and means for relatively moving said plates to firmlyengage a food product therebetween and means for maintaining a plate ata freezing temperature, whereby said product will be frozen through theagency of said plate while compressed between the two plates.

10. An apparatus for freezing foods comprisingtwo imperforate endlessmetal belts arranged in parallel relation with their adjacent reachesmoving in the same direction and engaging a Md product, means forflowing liquid freezing medium upon a defined intermediate portion ofthe upper surface of the lower reach of the uppermost belt, and meansfor the longitudinal flow of said freezing medium upon said belt.

vAnupparatus for freezin foods comprising an imperforate heat con uctiveplate adaptedto support a food product, a second imperforate heatconductive plate in adjustablespaced relation to said first plate, means,with' said second plate the upper surface of a food product supportedby said plate with any desired degree of presmeans to maintain the facesof said ates, while-confining said product thereso that said productwill be :3 desired degree through the plates. 12. An apparatus forfreezing foods comresprising an imperforate heatoonductive plate adaptedto support a food product, a second imperforate heat conductive plate,means automatically to engage with said second plate the upper surfaceof a product supported doby said first plate with any desired degree ofpressure, means to maintain thev faces of said plates at a temperatureto freeze said product while confined between said plates, and

means automatically to deliver the frozen article from engagement withsaid plates.

13. An apparatus for freezing foods comprising two imperforate surfacesspaced apart and arranged firmly to engage and confine between them afood product, means to freeze said product while engaged bysaidsurfaces, and means for automatically dcliyering the frozen productfrom engagement with and surfaces.

An apparatus for freezing foods compnsmg two imperforate heat conductivesurfaces spaced apart and arranged firmly to engage and confine betweenthem a food product, means for applying a freezing medium to the outerfaces of said surfaces while they are firmly engaging said product, andmeans for automatically delivering the frozen article fromengagement'with said surfaces.

15. An apparatus for freezing foods comprising an imperforate heatconductive member arranged to engage one side of a food product, asecond heat conductive member arranged automatically to engage the otherside of said product and to maintain it under a predetermined amount ofpressure, means for simultaneously separating said members and releasingthe product after a predetermined interval of time, and means formaintaining said members at a freezing temperature, whereby they act asagents for extracting heat from the article and freezing the same. 7

16. An apparatus for freezing foods having an imperforate 'heatconductive plate adapted to engage and support a food product, and meansfor supplying to the under surface of said plate a constant flow ofliquid freezing medium, said means comprising spray pipes from whichsaid liquid is sprayed upon the said under surface, whereby said platemay be maintained at substantially the same temperatureas said liquid.

17. An apparatus of. the character described'having an 'imperforate heatconductive plate adapted to engage and support a food product, meansspaced from the surface of the plate for spraying a freezing mediumagainst the same, constructed and arranged to permit the medium freelyto leave the plate, and means for collecting the medium so it may beused again.

18. An apparatus for freezing foods comprising two imperforate endlessmetal belts so positioned that one reach of each belt will be insubstantially parallel spaced relation with a reach of the otherbelt,said reaches being adapted to engage and confine between them afood product, pulleys for said belts, means to freeze an article whileengaged and confined between said belts, and means to move said belts insynchronism about said pulleys, said pulleys at the delivery end beingso relatively positioned that there will be asimultaneous separation'ofsaid belts to automatically disengage from a frozen ar-' ticle at saiddelivery end of said apparatus.

19. An apparatus for freezing foods comprising a metal plate adapted toengage a food product, a second metal plate, means to engage with saidsecond plate with any desired degree of pressure a food product engagedby said first plate, whereby said product will be compressed betweensaid plates, and means to freeze said product while com pressed betweensaid plates.

20. An apparatus for freezing foods comprising a metal plate adapted tosupport an article to be frozen, a second metal plate, means to engagewith said second plate the upper surface of a food product supported bysaid first plate with any desired degree of pressure, and means tofreeze an'article while engaged between said plates.

21. An apparatus fol-freezing foods comprising two imperforate heatconductive plates spaced apart and adapted to engage between them a foodto befrozen, a refrigerating chamber, means for moving said plates intoand out of said chamber, and means in said chamber for applying afreezing medium to the outer faces of said plates.

22, An apparatus for freezing foods comprising two imperfor ate heatconductive plates spaced apart and adapted to engage between them thefood to be frozen, a refrigerating chamber, means for moving said platesinto and out of said chamber, means in said chamber for applying afreezing medium to said plates and means to prevent said freezing mediumfrom engaging said'food.

I 23. An apparatus for freezing foods comprising an imperforate heatconductive plate adapted to engage and support a food product to befrozen, a refrigerating-chamber, means for moving said plate into andout of said chamber, and means in said chamber for spraying liquidfreezing medium againstsaid plate and for collecting said medium withinthe chamber after it leaves the plate.

24. An apparatus for freezing foods comprising surfaces adapted toengage and confine between them a food product to befrozen, means topositively press said surfaces into firm engagement with said productand means to simultaneously freeze said product.

25. An apparatus for freezing foods comprising two heat conductivesurfaces in spaced relation and adaptedto confine and compress betweenthem a food product to be frozen, means to adjust the spaced relation ofsaid surfaces, a refrigerating chamber, means to move said surfaces intoand out of said chamber, and means in said chamber for maintaining saidsurfaces at a freezing tempera ture.

26. An apparatus for freezing foods comprising two heat conductivesurfaces adapted to confine a food product to be frozen, pressure meansto compress saidarticlebetween said surfaces and means to maintain saidsurfaces at a freezing temperature while they are compressing saidproduct.

27. An apparatus for freezing foods comprising a refrigerating chamber,heat conductive surfaces adapted to engage and confine a food product tobe refrigerated, means to move said surfaces while confining said foodproduct into and outof said chamber, means within said chamberformaintaining said surfaces at a freezing temperature and positivepressure means for maintaining said surfaces in firm surfacew oontactwith said product while in said chamber.

An apparatus Ofl the character dey scribod-comprisinga refrigeratingchamber,

an imperforate belt conveyor a ted to engage and support ,an article ofood, means for moving said conveyor into and out of and means in saidchamber for down; a cooling medium over the outer face of said conveyor,and then collecting it within. the chamber after it leaves the conveyor.s v

29, Anapparatus for freezing foods compr'ming two impel-fonts endlessmetal belts adapted to engage between them a food product, aref ratingchamber, means for moving said ts into and out ofsaid chamber,andmeansinsaid v rfor applyinga mediumto the outer faces ofsaid taw s39. An apparatus for freezing foods comprising two endless metal beltsadaptedto engage-between them a food product, a refrigerating chamber,means for moving said beltldntoand outof said chamber, means in slidchamber for applying a freezing medium to thaouter faces 0 so belts andmeans to prevept said medium from engaging said cod product. p

81. An, ap

pr two imperforateiendless metal belts apart and adapted to confinebetween t on azfned product and means for applyin a freezing mediumtothe outer faces of sai sfihueby said belts act simultaneously extractheat from said food.

82. An apparatus for freezing foods comtwo endless in spaced relationand a apted to confine and com reasbetweentbemafoodproduct, p to justthe spaced relationo said he ts and means-to. maintain said belts at a nAn apparaims for prising two endless metal belts to'positively maintainsaid belts p in firm out with said f product, and means to. cool e outerfaces of the food confining rtions of said belts.

34. apparatus or freezi foods comnnperforate heat con uctive conveyor yA to adapted to confine between them a food product andmeans forapplying a freezing medium to theouter faces of sai belts.

35. apparatus of the character describedeomprising two endless metalbelts disposed ,above the other and adapted to engage in food productbetween the lower reach of the u per belt and the upaer reach of thelower be t the upper belt ing wider thanthe lower belt, and means forapplyin a refrigeratingfluid to the outer faces of are food reaches ofsaid belts.

86. An apparatus of the character dea paratus foods com-H rate metalbelts foods com adopted toconfine between-them a food product, means apluralit of rollers supported by reach of t e upper belt to maintainsaid reach scribed comprising two endless metal belts disposed one abovethe other and adapted to engage a food product between the lower reachof the up er belt and the u per reach of the lower be t, means forapplying a refrigerating fluid to the outer faces of the productengaging reaches of said belts and means to prevent said fluid fromentering the area between said reaches and engaging said product.

37. An apparatus for freezin foods' comprising a lower endless metal bet, a substantially unyielding support for the upper reach thereof, asecond. metal belt disposed above said first belt and with its lowerreach substantially parallel to the u per reach of said first belt, saidreaches o said belts bein adapted to confine between them a food prouct, a yieldingsupport'for the lower reach of said upper belt, ressuremeans to press said lower reach firm y against the support, and meansfor applying a freezing medium tothe outer faces of said reaches of saidbelts.

38. An apparatus of the character described comprising upper and lowermetal conveyors in substantially parallel relation and adapted toconfine between them a food roduct, a substantially unyielding su portor said lower conveyor, means for app ying a refrigerating fluid to theouter face of said up er conveyor, fluid confining supports for em upperconveyor, means for pressing said upper conveyor toward the lowerconveyor, whereby t e'upper conveyor will be pressed a ainst said foodroduct and wherey a flui seal joint will e formed between said conveyorand said supports to prevent the passa e of said refrigerating fluidintothe space etween said conveyors.

39, An apparatus for freezing foods comprising upper and lowerimperforate metal conveyors adapted to confine between them a foodproduct, means to move said conveyors.

in s chronism and means to appl a freezing me ium to the outer faces ofsai conve ors while the conveyors shield the product rom contact withsaid medium.

40. An apparatus for freezing foods com prising two endless metal beltsdisposed one above the other and adapted to enga a food product betweenthe upper reach of t e lower elt and the lower reach of the upper belt,the lower pressed firmly in engagement with said product, and means toap ly a freezing medium to the outer faces 0 said reaches of said belts.

41. An apparatus for freezing foods comprising two imperforate endlessmetal belts i sed one above the other and in substantla 1y arallelspaced relation and adapted to'con ne between them a food product, thelower belt extendin forwardly of the upper belt at the feed en of themachine, means to move said belts in synchronism whereby a food productsupported by said lower belt will be moved into engagement at its uppersurface with said upper belt, and means to freeze said product whilethus engaged by said belts.

42. An apparatus for freezing food products comprising two imperforateendless metal belts so positioned that one reach of each belt will be insubstantially parallel spaced relation with a reach of the other belt,said reaches being adapted to engage and confine between them a foodproduct, pulleys for said belts, means to freeze an article whileengaged and confined between said belt, and means to move said belts insynchronism about said pulle s, whereby said belts will engage said proucts at the feed end of the .apparatus andwill automatically disengagefrom said frozen article at the delivery end of said apparatus. I

43. An apparatus for freezing foods comprising upper and lowerimperforate metal conveyors adapted to confine between them a foodproduct, means for firmly supporting said lower conveyor, pressure meansfor pressing said upper conveyor against said article, said pressuremeans comprisinga plurality of rollers supported in spaced relation bysaid upper conveyor, means to move said conveyors and means to apply afreezing medium to the outer faces thereof while confining said product.

44. An apparatus of the character described comprising two endlessimperforate metal belts adapted to engage and confine between them afood product, a refrigerating chamber, means to move said belts into andout of said chamber, spray pipes adjacent the outer faces of said beltsin sald chamber and adapted to spray a freezing fluid on said outerfaces, means for supporting said conveyors in parallel spaced relationin said chamber, said supporting means engaging said belts adjacenttheir marginal edges with a fluid seal contact, and aprons dependingfrom said marginal supports, whereby sai fluid is prevented frompenetrating into the area between said belts.

45. An apparatus of the character described comprising two metal beltsdisposed one above the other and ada ted to engage and confine betweenthem a ood product, a refrigerating chamber, means to move said beltsinto and out of said chamber, means in said chamber to appl a freezingfluid to the outer face of the ower reach of the upper belt and a wiperheld in frictional engagement with said u per face adjacent the eliveryend of said c amber to revent the passage of freezing fluid from saidchamber on said belt.

46. An apparatus of the character described comprisin upper and lowerendless imperforate meta belts adapted to engage and confine between thelower reach of the upper belt and the up er reach of the lower belt aproduct to berozen, a refrigeratin chamber, means to move said reachesinto an out of said chamber, pressure means to maintain said reaches infirm engagement with said article, spray pipes in said chamber above thelower reach of the upper belt and below the upper reach of the lowerbelt and adapted to spray a freezing fluid upon the outer faces of saidreaches, and means to prevent said fluid from penetrating into the areabetween said reaches.

47. An apparatus for freezing foods comprising surfaces adapted toengage and confine between them a food product to be frozen, means topress said surfaces into firm engagement with said product with auniform pressure regardless of the thickness of the product, and meansto simultaneously freeze said product.

48. An apparatus for freezing foods comprising two plates adjustablysupported in spaced relation and adapted to engage between them foodproducts of varying thicknesses and maintain under continuous pressure aproduct thus engaged and means to freeze said food while engaged andcompressed by said plates.

49. An apparatus for freezing foods comprising two plates supported inspaced relation and adapted to engage between them a food product andmamtain said product under uniform pressure and means to freeze saidfood while engaged and compressed by said plates.

50. An apparatus for freezing foods comprising two plates supported inspaced relation, and adapted to engage between them a food product,means for varyin said spaced relation and compressing said p atesagainst said food roduct with uniform pressure and means to reeze saidfood while engaged and compressed by said plates.

In testimony whereof I have signed my name to this specification.

CLARENCE BIRDSEYE.

